Do you know your car's MoT and mileage history? Our user profiles will show you for FREE | No thanks
99 1.25 zetec misfire/power loss - Help please! - Kyle_leeds
Hi guys,

I've had nothing but problems with my Fiesta 1.25 Zetec since I bought it approx 3 months ago. It's my first car so I can't afford to drop it off at the garage every time something goes wrong (since all my spare money is paying for my extortionate insurance).

After 2 months my clutch fully failed, this has since been rectified but around two weeks after that the engine seems to have lost power and is misfiring.

I've fitted a new fuel filter and set of spark plugs, which has increased the engine power, however it still doesn't feel as good as it was.

My main concern is the engine is now misfiring, both when running and when idling. My revs seem to be going quite high when in low gears as well. It also seems to be spluttering a bit when starting up (thought it still starts first time almost always) and the exhaust is 'chuffing' quite loudly.

I've been advised by a friend of mine that it is likely a fault on the fuel line and could be the HT leads, coilpack or injectors.

I'm getting no engine warning lights on at any point, and the car runs alright(ish) at the minute, but I am sure it is just a matter of time before it gives up on me again.

If anyone has any experience or advice regarding any of the faults I've mentioned I would really appreciate your advice and suggestions.


Tags: technical issues legal and consumer advice starting problem electrical faults

99 1.25 zetec misfire/power loss - Help please! - Screwloose
After 2 months my clutch fully failed this has since been rectified

My revs seem to be going quite high when in low gears as well.

Are you sure that you don't still have a clutch problem?

The misfire should have been noticed by the ECU; but try a secondhand coilpack as the cheapest test.
99 1.25 zetec misfire/power loss - Help please! - Andrew Moorey (Tune-Up)
Coil packs and leads are a weak point on these and most 16v Fords, however the Fiesta I looked at yesterday had zero compression on cylinder 2 so the head is coming off that one to check for a damaged valve or piston.
I'd start by looking at the old plugs if you have them still by looking for a thin burn mark down the porcelain which the plug lead slips over. If you dont have them check the new ones. This burn mark is the spark tracking down the side of the plug rather than through it into the cylinder. If this is the case renew the lead and the plug (You can buy them individually from Ford) If not start the engine and starting at one end CAREFULLY pull the plug lead up slightly from the plug (I use long nosed pliers) and as you do you will hear the spark crack when jumping the large gap, repeat for each cylinder and you may then come across one that is silent because there is a) no spark or b) the lead is faulty. If they all crack the fault is more likely to be mechanical. (I've never had an injector fail on one of these) But you may find as you lift the leads the engine suddenly picks up onto 4 cylinders, this would indicate a plug fault and the huge spark being generated is powerful enough to jump even a fouled plug.
I know this is a bit 'bush mechanics' but i find its the quickest diagnosis. Goes without saying to be careful with HT voltage.......
99 1.25 zetec misfire/power loss - Help please! - Kyle_leeds
Hi Andrew,

I've tried pulling the plugs out and didnt get a spark through one of them at all. I don't have the old plugs I'm afraid, but I'll have a check for burn marks on the new plugs tomorrow though.

Is a new HT lead/plug the next best step, assuming there is no burn mark on the new plugs?

Thanks mate.

99 1.25 zetec misfire/power loss - Help please! - Kyle_leeds
Checked this out, one of the HT cables had corroded and another had split. Patched these up for the minute until I can get some new cables. Any recommendations about where is the best place to buy a new set from?

99 1.25 zetec misfire/power loss - Help please! - Screwloose

99 1.25 zetec misfire/power loss - Help please! - Kyle_leeds
Working a treat now, thanks for all the advice everyone.

Ask Honest John

Value my car

Amount to borrow
Sorry. The minimum loan amount is £1000
To pay back over

My credit score

Best available rate 9.20%

Total repayment £9,304.93

Total cost of credit £1,804.93


60 monthly payments

Apply now

Representative example

The Representative APR is 13.2% (fixed) so if you borrow £7,500 over 4 years at a rate of 13.2% p.a (fixed) you will repay £199.21 per month and repay £9562.20 in total.